1. Filed of the Invention
This invention relates to automobile wheels. More particularly, it relates to the wheels to be used temporarily in case of damage to a pneumatic tire, or else in case of driving under difficult conditions, such as in mud or snow.
2. Background of the Invention
At present, when one of the pneumatic tires mounted on the wheels of a vehicle has suffered a puncture, it is necessary to remove the wheel concerned and replace it with a reserve wheel, commonly called a spare wheel. Another possibility known in the art consists of mounting a spare wheel beside the deflated pneumatic tire, without removing the latter. An illustration of this is found in patent GB 967 397. Hereinafter, such a spare wheel will be called an "auxiliary wheel," and the wheel normally mounted on the vehicle, with which the auxiliary wheel will be paired in case of damage to the pneumatic tire mounted on the main wheel, will be called a "main wheel."
These auxiliary wheels have not found practical application, although they are very appealing in theory since the installation operations are simplified relative to the replacement of one wheel by another.
The unresolved difficulty in the art consists in reconciling two contradictory requirements. It is necessary that the means of fastening the auxiliary wheel to the main wheel make possible an extremely simple handling for the driver, so that the use of such an auxiliary wheel will confer a major advancement relative to the standard use of a spare wheel. It also is necessary that the means of fastening be solid enough to hold the auxiliary wheel absolutely parallel to the main wheel, so that the use of such an auxiliary wheel can be made with a sufficient level of reliability.
Further, the weight and the overall dimensions of such an auxiliary wheel should compare favorably with those of a spare wheel, in particular with a temporary use type spare wheel as is found on some vehicles. It also is necessary that the mounting of the auxiliary wheel on the main wheel does not involve for the latter a substantial increase in weight, a large increase in cost or a deterioration of aesthetic appearance.